Various surgical devices are known for compressing and cutting different types of tissue. In general, these devices have an end effector, such as a pair of opposed jaw members, that is configured to engage tissue and a cutting mechanism that is configured to sever tissue engaged by the end effector. Certain of these devices can also be configured to apply energy, such as radio frequency (RF) electrical energy, to the tissue disposed between the jaws. The application of electrical energy in the vicinity of a tissue cut can seal the cut to prevent bleeding of the tissue, leakage of other fluids through the cut, etc.
Many surgical devices used for compressing and cutting tissue are manually operated, such that a user has to provide an actuation force through, for example, a handle portion of a device coupled to the end effector. However, the forces required to operate such a device on thick or tough tissue can exceed the strength of some operators and may fatigue others. In an effort to address this problem, certain surgical devices include electric motors to provide the necessary actuation force. This reduces the amount of force required from a user, as the user need only actuate a button, switch, or other electrical actuation mechanism.
A common concern with electrically-powered surgical devices is the lack of control and tactile feedback that is inherent to a manually-operated device. Surgeons and other users accustomed to manually-operated devices often find that electrically-powered devices reduce their situational awareness because of the lack of feedback from the device. For example, electrically-powered devices do not provide users with any feedback regarding the progress of a cutting and/or sealing operation (e.g., an actuation button or switch is typically binary and provides no feedback on how much tissue has been cut, etc.) or the forces being encountered (e.g., toughness of the tissue). This lack of feedback can produce undesirable conditions. For example, if a motor's power is not adequate to compress and transect tissue the motor can stall out. Without any feedback to a user, the user may maintain power during a stall, resulting in excessive heating within the device. Furthermore, even if the stall is discovered, users often cannot correct the stall by reversing the motor to retract the cutting mechanism because a greater amount of force is available to advance a cutting mechanism than is available to reverse it (e.g., due to inertia when advancing). As a result, time-intensive extra operations can be required to free the stalled cutting element and disengage the device from the tissue.
In addition, electrically-powered devices can be less precise in operation than manually-operated devices. For example, users of manually-operated devices are able to instantly stop the progress of a cutting mechanism by simply releasing the actuation mechanism. With an electrically-powered device, however, releasing an actuation button or switch does not result in instantaneous halting of a cutting element, as the electric motor will continue to drive the cutting element until the kinetic energy of its moving components is dissipated. As a result, a cutting element may continue to advance for some amount of time even after a user releases an actuation button.
Still further, the introduction of motor controls in addition to controls for the delivery of RF or other energy to seal tissue can overwhelm an operator by requiring simultaneous management of multiple controls. Separate controls can be combined in certain devices to reduce the number that must be managed by a user, but this often reduces the control of the various functions that is possible by the operator.
Accordingly, there is a need in the art for improved devices and methods that provide greater control over, and feedback from, electrically-powered surgical devices.